int
trace_read (trace_t * t)
{
int len;
unsigned char data[56]; /* For a TIME_EXCEEDED datagram. */
struct ip *ip;
icmphdr_t *ic;
socklen_t siz;
assert (t);
siz = sizeof (t->from);
len = recvfrom (t->icmpfd, (char *) data, 56, 0,
(struct sockaddr *) &t->from, &siz);
if (len < 0)
error (EXIT_FAILURE, errno, "recvfrom");
icmp_generic_decode (data, 56, &ip, &ic);
switch (t->type)
{
case TRACE_UDP:
{
unsigned short *port;
if ((ic->icmp_type != ICMP_TIME_EXCEEDED
&& ic->icmp_type != ICMP_DEST_UNREACH)
|| (ic->icmp_type == ICMP_DEST_UNREACH
&& ic->icmp_code != ICMP_PORT_UNREACH))
return -1;
/* check whether it's for us */
port = (unsigned short *) &ic->icmp_ip + 11;
if (*port != t->to.sin_port)
return -1;
if (ic->icmp_code == ICMP_PORT_UNREACH)
/* FIXME: Ugly hack. */
stop = 1;
}
break;
case TRACE_ICMP:
if (ic->icmp_type != ICMP_TIME_EXCEEDED
&& ic->icmp_type != ICMP_ECHOREPLY)
return -1;
if (ic->icmp_type == ICMP_ECHOREPLY
&& (ic->icmp_seq != pid || ic->icmp_id != pid))
return -1;
else if (ic->icmp_type == ICMP_TIME_EXCEEDED)
{
unsigned short *seq = (unsigned short *) &ic->icmp_ip + 12;
unsigned short *ident = (unsigned short *) &ic->icmp_ip + 13;
if (*seq != pid || *ident != pid)
return -1;
}
if (ip->ip_src.s_addr == dest.sin_addr.s_addr)
/* FIXME: Ugly hack. */
stop = 1;
break;
/* FIXME: Type according to RFC 1393. */
default:
break;
}
return 0;
}
int ping_recv (PING * p)
{
socklen_t fromlen = sizeof (p->ping_from.ping_sockaddr);
int n, rc;
icmphdr_t *icmp;
struct ip *ip;
int dupflag;
n = recvfrom (p->ping_fd,
(char *) p->ping_buffer, _PING_BUFLEN (p, USE_IPV6), 0,
(struct sockaddr *) &p->ping_from.ping_sockaddr, &fromlen);
if (n < 0)
return -1;
rc = icmp_generic_decode (p->ping_buffer, n, &ip, &icmp);
if (rc < 0)
{
/*FIXME: conditional */
fprintf (stderr, "packet too short (%d bytes) from %s\n", n, inet_ntoa (p->ping_from.ping_sockaddr.sin_addr));
return -1;
}
switch (icmp->icmp_type)
{
case ICMP_ECHOREPLY:
case ICMP_TIMESTAMPREPLY:
case ICMP_ADDRESSREPLY:
/* case ICMP_ROUTERADV: */
if (icmp->icmp_id != p->ping_ident)
return -1;
if (rc)
fprintf (stderr, "checksum mismatch from %s\n", inet_ntoa (p->ping_from.ping_sockaddr.sin_addr));
p->ping_num_recv++;
if (_PING_TST (p, icmp->icmp_seq))
{
p->ping_num_rept++;
p->ping_num_recv--;
dupflag = 1;
}
else
{
_PING_SET (p, icmp->icmp_seq);
dupflag = 0;
}
if (p->ping_event.handler)
(*p->ping_event.handler) (dupflag ? PEV_DUPLICATE : PEV_RESPONSE,
p->ping_closure,
&p->ping_dest.ping_sockaddr, &p->ping_from.ping_sockaddr, ip, icmp, n);
break;
case ICMP_ECHO:
case ICMP_TIMESTAMP:
case ICMP_ADDRESS:
return -1;
default:
if (!my_echo_reply (p, icmp))
return -1;
if (p->ping_event.handler)
(*p->ping_event.handler) (PEV_NOECHO,
p->ping_closure,
&p->ping_dest.ping_sockaddr, &p->ping_from.ping_sockaddr, ip, icmp, n);
}
return 0;
}
int
icmp_echo_decode (unsigned char * buffer, size_t bufsize,
struct ip **ipp, icmphdr_t ** icmpp)
{
return icmp_generic_decode (buffer, bufsize, ipp, icmpp);
}